Dishwasher or the like



Feb. 8, 1955 c. HOLLERITH 2,

DISHWASHER 0R THE-LIKE s sheeis-sheetl Filed May 1, 1953 v INVENTOR.(/JARLES HOLLE/Z/Th A TTOR NEY Feb. 8, 1955 Filed May 1, 1953 C.HOLLERITH DISHWASHER OR THE LIKE 3 Sheets-Sheet 2 JNVENTOR. //01 1. 5/2/77/ ATTO/P/VE Y Feb. 8, 1955 Filed May 1, 1953 C. HOLLERITH DISHWASHEROR THE LIKE 3 SheetsSheet 3 I N V EN TOR LHARLEJ HOLLER/TH A TTQR/VEYUnited States Patent DISHWASHER OR THE LIKE Charles Hollerith, Jackson,Mich., assignor, by mesne assignments, to The Apex ElectricalManufacturing Company, Cleveland, Ohio, a corporation of OhioApplication May 1, 1953, Serial No. 352,347

2 Claims. (Cl. 134-57) lating system for delivering liquid to themachine vat under pressure and returning said liquid to the pump forrecirculation is provided w th means for mll'llIIllZlng noise created byliquid pulsations emanatmg from the pump and vibrations, primarilytorsional, occurring in the motor-pump unit. It is well known that indish washing machines of the above type, the pump creates l1qu1dpulsations in the conduit extending from the pump to the vat, and sincethe vat acts like a sounding board to some degree, considerableundesirable noise is created. I provide a relatively long conduit orhose formed of soft rubber and extending between the pump and vat, andthe expansion and contraction of the hose largely damps or smoothes outthe pulsations before reaching the vat. Further, vibrations, primarilytorsional, occur in the motor-pump unit and if such vibrations aredirectly transmitted to the machine, the noise level is substantiallyincreased. I provide a resilient mounting for the motorpump unit andhave found that this type mounting coupled with the long and expansiblewater passage between the pump and vat results in a relatively quietoperating dishwasher.

It is a primary object of the invention to provide in a dishwashingmachine having a liquid circulating system,

including a pump, means for minimizing transmission of I vibration andresultant noise during circulation of liquid.

Another object of the invention is to provide in a dishwashing machineof the above type having a built-in heater tank, a relatively simpleliquid supply, circulating and drainage system.

Another object of the invention is to provide a dishwashing machine ofthe above type having a built-in heater tank disposed beneath thearticle receiving vat adapted to be gravity filled and having associatedmeans for lifting the water from the heater tank into the articlereceiving vat.

Other objects of the invention and the invention itself will becomeincreasingly apparent from a consideration of the following descriptionand drawings, wherein:

Figure l is an elevational view, partially in section,

and with parts omitted for clearness of illustration, of a dishwashingmachine embodying the invention;

Figure 2 is a longitudinal, sectional view of a heater tank I mayemploy;

Figure 3 is a sectional view of a cam operated valve means I may employ;

Figure 4 is a view of a timer and valve means I may p y;

Figure 5 is a side elevational view showing the mounting means for themotor-pump unit;

Figure 6 is an end elevational view of the unit shown in Fig. 5; and

Figure 7 is a wiring diagram showing a preferred electrical hook-up forthe dishwasher.

Referring now to the drawings, and particularly Figure l, I haveindicated the dishwasher vat or tub at 10.

Patented Feb. 8, 1955 The vat or tub 10 has a hinged lid (not shown)with an associated safety switch 10' (Figure 7). The vat base 11 isformed to drain to a sump 12 which through a conduit 13 connects with apump 14 driven by an electric motor The pump is preferably of the typehaving a twobladed impeller working in a water-tight chamber whereinliquid is received through an axial inlet- 17 and dischargedundervpressure from a tangential outlet 18. A Venturi fitting 19connects conduit 13 and pump inlet 17, the Venturi fitting having arelatively reduced lateral inlet port communicating with a conduit 21extending from an inlet valve 22 which forms part of a timer and valveassembly generally indicated at 23.

A second conduit 24 extends to the inlet valve from a heater tank 26. Atthe opposite or upper end of assembly 23 is a drain valve 27 having arelatively long drain hose 28 terminating in a hook portion 29 adaptedto be hooked over the edge of a sink, set tub or the like. A conduit 31also extends from the drain valve to a T fitting 32 connected to theoutlet 18 of the pump. A relatively long and preferably looped conduit33 formed of relatively soft rubber extends from fitting 32 to a fitting34 sealed to the base of vat 10 and forming a swivel mounting for aspinner arm 36 within the vat. Arm 36 is provided with a plurality ofjet nozzles 37 whereby when water is supplied under pressure to arm 36,the arm will be caused to rotate by the reaction of water jets issuingfrom the nozzles. Depending blades 38 limit the speed of rotation of arm36 when operating in liquid.

The heater tank 26, suitably insulated, has a cup form body 39 and ahead 41 sealingly secured thereto. A U form electric immersion heater 42is adapted to heat or maintain liquid in the tank at a predeterminedtemperature and a float type safety switch 43 is adapted to prevent theheater circuit from being energized unless there is water in the tank toa predetermined level. The tank is filled through a hose 44 having abulb'type connector 46 for engagement with a faucet. The connector 46 isforced over the faucet spout and is resilient to be adaptable to variousshapes of faucet spouts, and since the tank is filled by gravity, thereis little pressure at the faucet connection. When the tank is filled,water overflows through a conduit 47 into a cup 48 encasing an openingin the vat side wall whereby water flowing into the vat 10 indicatesthat the heater tank 26 is filled. This arrangement provides a vacuumbreak preventing reverse flow of water from the vat back into the tank.A thermostat 49 is mounted in the top zone of tank 26 for a purpose tobe described. Thermostat 49 is connected with a float switch 49' (Figure7) operating in the heater tank 26 and the purpose of which float switchis to close the timer motor circuit when the water level in the heatertank falls to a predetermined level.

The drain valve 27 is best illustrated in Figure 3 and comprises a castmetal housing 51 having a lateral extension or sleeve 52 for connectionwith drain hose 28 and a second sleeve 53 for connection with conduit31. The upper portion of the housing is sealed by a removable plug 54which forms a seat for one end of a compression spring 56, the lower orother end of the spring bearing against the stem of a valve 57 and tendsto hold the valve against the seat 58. The lower portion of the valvestem is slidable in the vertical portion of the housing 51 and an O ringtype seal 59 prevents leakage therebetween. The valve stem at its lowerportion is forked to ride at either side of a cam disc 66 and to receivea cam roller 62. A conventional timer electric motor 63 rotates the camshaft 65 whereby when the lift portion 64 of the cam engages roller 62,the valve 57 will be lifted from its seat 58 permitting water to flowfrom conduit 31 to drain hose 28. The inlet valve 22 is similarlyconstructed and is operated by'a second cam 61 whereby when this valveis open water will flow from conduit 24 to conduit 21. A third cam 67 isadapted to break the circuit to the timer motor at the completion of thecycle.

The manual control knob, indicated at in Fig. 4, can be operated torotate cam 88' which will close switch 88 and condition the circuits ofthe timer motor 63 and heater 42 for energization. Thereafter if the lidsafety switch 10 is closed the timer motor will operate if either thethermostatic switch 49 or the thermostat float switch 81 encircle rods79 If there is insuflicient water 49' is closed and the heater 42 willbe energized if the heater float switch 43 is closed, assuming the timermotor is operating due to closure of switch 49 and the pump is operatingto draw water from heater tank 26. Under these conditions it thethermostat should cool or switch 49 should open for any reason thecircuit to the timer motor 63 would be broken and the machine wouldcontinue to operate indefinitely, unless some arrangement is providedfor having the timer complete the cycle. The float switch 49'accomplishes this result since when a predetermined low water level inthe heater tank 26 is reached, switch 49' closes to place the timermotor in circuit to complete the cycle.

Referring now to Figures and 6, the manner in which the motor-pump unitis mounted will now be explained. The parts illustrated in Figure 1 areencased in a cabinet (not shown) and a pair of angle members 71 aresecured in any suitable manner to the cabinet frame structure to providea rigid support. A pair of L section plates 72 are secured to thehousing of motor 16 by bolts 73. The plates 72 have an upper portionconforming in contour to the motor housing and a horizontally extendingportion provided with spaced holes. Step form, perforated, cup shapedelements 76 have the section of reduced diameter projected through theholes and the enlarged lower portion which abuts plates 72 forms a seatfor the upper end of springs 77. Cup members 78, which rest on members71, form seats for the lower ends of springs 77. Rods 79, preferablyformed of hexagonal stock, have a reduced threaded section at each endforming shoulders against which lower cup members 78 and similar uppercup members abut. Upper springs with the lower ends of the springsseating on the horizontal portion of plates 72 and the reduced diametersection of cup elements 76 projecting upwardly within the lowerconvolutions of springs 81 to limit lateral movement of the springs.Lock washers 82 and nuts 83 threaded to rods 79 hold the lower ends ofthe rods and lower cup members 78 in firm engagement with members 71 andthe upper cup members 78 in firm engagement with the upper end of therods. The lower springs 77 which take the load of the motor-pump unithave a higher rating or are relatively stronger than the upper springs81 which serve to dampen vibrations. The hexagonal rods 79 pass throughopenings 76' in re-' duced upper portions of the cup elements 76 withall round clearance, whereby to permit the motor-pump unit to partake oflimited horizontal floating movement. It will be noted that the springsare outboard of the motor or spaced some distance from the verticalcenter line of the motor which increases their effectiveness in dampingtorsional vibration. For example, if the ngotor tends to rotate in agiven direction, this tendency is yieldingly resisted by one lowerspring 77 and the opposite upper spring 81. It is desirable that thelower springs 77 have as low a rating as possible consistent with theirability to support the motor-pump unit.

The operation of the dishwashing machine will now be described withreference to the wiring diagram illustrated in Figure 7. The bulbconnector 46 is secured to the spout of a house hot water faucet, andwhen the faucet is turned on, hot water flows into heater tank 26 untilit overflows into vat indicating the heater tank is full. Power leadsare indicated at 86 and 87. With the lid safety switch 10' closed, ifswitch 88 is closed by rotating cam 88' through manual control knob 90the heater 42 is energized and timer motor 63 is placed in circuit withthe thermostat 49 and float switch 49'. When the temperature of thewater in heater tank 26 reaches a predetermined temperature thermostat49 closes and the timer motor is energized. Thereafter the cam 67' willoperate to close switch 67 and thus energize the pump motor 16. in theheater tank 26 to close the float switch 43 the heater 42 (and lamp)will not be energized. After the timer motor starts operating the firstrise 64 of the cam disc lifts valve 57 of inlet valve 22, permittingwater to flow to pump 14 and thence through conduit or hose 33 to rotaryarm 36. It will be noted that hose 33 is relatively long and the hose 18formed of relatively soft rubber whereby the hose may readily expand andcontract to dampen or smooth out liquid pulsations emanating from thepump before the pulsations reach vat 10. Water discharged into the vatfrom jet nozzles 37 is returned to the pump for recircuthrou h conduit21, against the head of water in conduit .son skilled in the art.

13. uring the commencement of the washing period the inlet valve 22 isopenedbut is closed for the remainder of the washing period, the drainvalve 27 being opened at the end of the washing period, whereby the pumdischarges wash water through drain hole 28 to a sin or the like.

In a dishwasher having a recirculating liquid system ,as described, itis desirable to usean impeller type pump and preferably having impellerblades formed of rubber or the like to be sutficiently flexible to passfood particles and the like removed from articles being washed withoutdanger of clogg ng the pump. This results in a pulsating act on as wateris picked up at the axial inlet of the pump, whirled towards theperiphery of the pump casing, and is discharged to hose 33 through thetangential outlet for the pump. Shnce water is relativelyincompressible, this would result in successive impacts or vibrationswhich would be directly transmitted to the machine if the motor.

were rigidl y mounted or if a conduit of short length or relativelyrigid material leading to vat 10 were used, since, to some degree, thevat acts as a sounding board. This would result in highly objectionablenoise. I have found that by providing a resilient or limited floatingmounting for the motor-pump unit, plus providing a relatively longconduit formed of relatively soft rubber and extending from the pumpoutlet to the vat, the noise is very substantially reduced. In effect,the soft rubber hose expands and contracts tending to smooth out ordampen the pulsations before they reach the vat. These pulsations willoccur to a greater or less degree regardless of the type pump used.

I have described the invention in connection with a dishwashing machinehaving a built-in storage tank adapted to be gravity filled, but it isunderstood that the invention is equally adaptable to a machine having atank permanently connected to a water supply line or a machine not equpped with a built-in tank, but requiring a water circulating system ofthe general type described. In other words, the wash and rinse watercould be directly introduced nto vat 10.

I wish it to be understood that I do not desire to be limited to theexact details of construction shown and described for obviousmodifications will occur to a per- What I claim is: i

1. In a dishwashing machine, the combination of a vat, a; motor-pumpunit mounted beneath the vat, and a liquid circulating system fordelivering water to the vat under pressure and returning liquid from thevat to the pump, said circulating system comprising a built-in heatertank adapted to receive liquid for washing and rinsing operations, annlet valve, a drain valve, timer means for operating said valves insequence, conduit means extending from the tank to the inlet valve, acontinuously open co iduit extending from the vat to the pump, communicating means between the inlet valve and pump, and communicatingmeans-between the drain valve and pump whereby when the inlet valve isopened for a predetermined period liquid from the tank will be deliveredto the liquid circulating system for recirculation through the yet bythe pump and when the drain valve is open liquid from the vat will bedischarged.

2. The combination as described in claim 1, and wherev in the heatertank is adapted to be gravity filled, an electrically energizable heateris disposed in the tank, a float switch prevents energization of saidheater until a predetermined level of liquid is attained in the tank,and a thermostatic switch controlling the timer motor is mainta ned openuntil a predetermined temperature is attamed in the tank.

References Cited in the file of this patent UNITED STATES PATENTS

